AT89C2051 Atmel Corporation, AT89C2051 Datasheet



Manufacturer Part Number
Atmel Corporation

Specifications of AT89C2051

Flash (kbytes)
2 Kbytes
Max. Operating Frequency
24 MHz
Max I/o Pins
Sram (kbytes)
Operating Voltage (vcc)
2.7 to 6.0
Compatible with MCS
2K Bytes of Reprogrammable Flash Memory
– Endurance: 10,000 Write/Erase Cycles
2.7V to 6V Operating Range
Fully Static Operation: 0 Hz to 24 MHz
Two-level Program Memory Lock
128 x 8-bit Internal RAM
15 Programmable I/O Lines
Two 16-bit Timer/Counters
Six Interrupt Sources
Programmable Serial UART Channel
Direct LED Drive Outputs
On-chip Analog Comparator
Low-power Idle and Power-down Modes
Green (Pb/Halide-free) Packaging Option
1. Description
The AT89C2051 is a low-voltage, high-performance CMOS 8-bit microcomputer with
2K bytes of Flash programmable and erasable read-only memory (PEROM). The
device is manufactured using Atmel’s high-density nonvolatile memory technology
and is compatible with the industry-standard MCS-51 instruction set. By combining a
versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89C2051 is a power-
ful microcomputer which provides a highly-flexible and cost-effective solution to many
embedded control applications.
The AT89C2051 provides the following standard features: 2K bytes of Flash, 128
bytes of RAM, 15 I/O lines, two 16-bit timer/counters, a five vector two-level interrupt
architecture, a full duplex serial port, a precision analog comparator, on-chip oscillator
and clock circuitry. In addition, the AT89C2051 is designed with static logic for opera-
tion down to zero frequency and supports two software selectable power saving
modes. The Idle Mode stops the CPU while allowing the RAM, timer/counters, serial
port and interrupt system to continue functioning. The power-down mode saves the
RAM contents but freezes the oscillator disabling all other chip functions until the next
hardware reset.
with 2K Bytes

Related parts for AT89C2051

AT89C2051 Summary of contents

Page 1

... Atmel’s high-density nonvolatile memory technology and is compatible with the industry-standard MCS-51 instruction set. By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89C2051 is a power- ful microcomputer which provides a highly-flexible and cost-effective solution to many embedded control applications. ...

Page 2

... Pin Configuration 2.1 20-lead PDIP/SOIC 3. Block Diagram AT89C2051 2 RST/VPP 1 20 VCC (RXD) P3 P1.7 (TXD) P3 P1.6 XTAL2 4 17 P1.5 XTAL1 5 16 P1.4 (INT0) P3 P1.3 (INT1) P3 P1.2 (TO) P3 P1.1 (AIN1) (T1) P3 P1.0 (AIN0) GND 10 11 P3.7 0368H–MICRO–6/08 ...

Page 3

... I/O pin. The Port 3 output buffers can sink 20 mA. When 1s are written to Port 3 pins they are pulled high by the internal pull-ups and can be used as inputs. As inputs, Port 3 pins that are externally being pulled low will source current (I Port 3 also serves the functions of various special features of the AT89C2051 as listed below: Port Pin P3.0 P3 ...

Page 4

... Figure 5-1. Note: Figure 5-2. AT89C2051 4 Oscillator Connections C1 ± for Crystals = 40 pF ± for Ceramic Resonators External Clock Drive Configuration Figure 5-1 ...

Page 5

... User software should not write 1s to these unlisted locations, since they may be used in future products to invoke new features. In that case, the reset or inactive values of the new bits will always be 0. Table 6-1. AT89C2051 SFR Map and Reset Values 0F8H B 0F0H 00000000 ...

Page 6

... AT89C2051. This should be the responsibility of the software programmer. For example, LJMP 7E0H would be a valid instruction for the AT89C2051 (with 2K of memory), whereas LJMP 900H would not. ...

Page 7

... Programming The Flash The AT89C2051 is shipped with the 2K bytes of on-chip PEROM code memory array in the erased state (i.e., contents = FFH) and ready to be programmed. The code memory array is pro- grammed one byte at a time. Once the array is programmed, to re-program any non-blank byte, the entire memory array needs to be erased electrically ...

Page 8

... RST to “L” Turn V Data Polling: The AT89C2051 features Data Polling to indicate the end of a write cycle. During a write cycle, an attempted read of the last byte written will result in the complement of the writ- ten data on P1.7. Once the write cycle has been completed, true data is valid on all outputs, and the next cycle may begin ...

Page 9

... The internal PEROM address counter is reset to 000H on the rising edge of RST and is advanced by a positive pulse at XTAL1 pin. 2. Chip Erase requires PROG pulse. 3. P3.1 is pulled Low during programming to indicate RDY/BSY. 0368H–MICRO–6/08 RST/VPP P3.2/PROG 12V H H Bit - 1 12V Bit - 2 12V 12V H H AT89C2051 P3.3 P3.4 P3 (2) ...

Page 10

... Figure 13-1. Programming the Flash Memory Figure 13-2. Verifying the Flash Memory AT89C2051 10 PP 0368H–MICRO–6/08 ...

Page 11

... PROG High to BUSY Low GHBL t Byte Write Cycle Time WC t RDY/BSY\ to Increment Clock Delay BHIH t Increment Clock High IHIL Note: 1. Only used in 12-volt programming mode. 15. Flash Programming and Verification Waveforms 0368H–MICRO–6/08 PP AT89C2051 Min Max Units 11.5 12.5 V 250 µA 1.0 µs 1.0 µs 1.0 µs 10 µ ...

Page 12

... Under steady state (non-transient) conditions, I Maximum I per port pin Maximum total I for all output pins exceeds the test condition than the listed test conditions. 2. Minimum V for Power-down is 2V. CC AT89C2051 12 *NOTICE: Condition (Except XTAL1, RST) (XTAL1, RST mA mA 2.7V ...

Page 13

... Clock Rising Edge to Input Data Valid XHDV 0368H–MICRO–6/ 2.7V to 6.0V CC Min Max MHz Osc Min Max 1.0 700 700 AT89C2051 V = 4.0V to 6.0V CC Min Max Units 0 24 MHz 41 Variable Oscillator Min Max Units 12 t µ ...

Page 14

... Float Waveforms Note: 1. For timing purposes, a port pin is no longer floating when a 100 mV change from load voltage occurs. A port pin begins to float when 100 mV change from the loaded V AT89C2051 14 (1) - 0.5V for a logic 1 and 0.45V for a logic 0. Timing measurements are made level occurs ...

Page 15

... C Vcc=5. FREQUENCY (MHz) AT89C2051 TYPICAL ICC vs. VOLTAGE- POWER DOWN (85° µ 3.0V 4.0V Vcc VOLTAGE Notes: 1. XTAL1 tied to GND 2. P.1.0 and P1 GND CC 3. Lock bits programmed AT89C2051 Vcc=6.0V Vcc=5.0V Vcc=3. Vcc=6.0V Vcc=3. 5.0V 6.0V 15 ...

Page 16

... Wide, Plastic Dual In-line Package (PDIP) 20S 20-lead, 0.300” Wide, Plastic Gull Wing Small Outline (SOIC) AT89C2051 16 Ordering Code Package AT89C2051-12PU 20P3 AT89C2051-12SU 20S AT89C2051-24PU 20P3 AT89C2051-24SU 20S Package Type Operation Range Industrial (-40° 85° C) Industrial (-40° 85° C) 0368H–MICRO–6/08 ...

Page 17

... Mold Flash or Protrusion shall not exceed 0.25 mm (0.010"). 2325 Orchard Parkway San Jose, CA 95131 R 0368H–MICRO–6/08 D PIN TITLE 20P3, 20-lead (0.300"/7.62 mm Wide) Plastic Dual Inline Package (PDIP) AT89C2051 E1 A1 COMMON DIMENSIONS (Unit of Measure = mm) SYMBOL MIN NOM A – – A1 0.381 – D 24.892 – ...

Page 18

... SOIC AT89C2051 18 0368H–MICRO–6/08 ...

Page 19

... Atmel products are not suitable for, and shall not be used in, automotive applications. Atmel’s products are not intended, authorized, or warranted for use as components in applications intended to support or sustain life. © 2008 Atmel Corporation. All rights reserved. Atmel Atmel Corporation or its subsidiaries. Other terms and product names may be trademarks of others. International Atmel Asia ...

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